International Dredging Review

International Dredging Review

ENCO Dredging Helps Mississippi’s Coastal Restoration Program

By Lara Lightsey
Marketing Director
Dredging Supply Company LLC

While driving alongside Beach Boulevard in Pascagoula Mississippi the average person would never know that just six months earlier the majority of that beach didn’t exist. It’s hard to imagine that a beach was just created out of nowhere but that’s exactly what the U.S. Army Corps of Engineers Mike Hooks Inc. and Gulf Sand & Gravel Inc. dba ENCO Dredging did during their collaboration on the Pascagoula Beach Boulevard project as part of the Mississippi Coastal Improvements Program (MsCIP).

The Pascagoula River also referred to as Mississippi’s “Singing River” flows southward through the heart of the state’s swamps before reaching the Gulf of Mexico in a rich network of channels and bayous. The river serves as a host to a great deal of industry in the surrounding area including Northrop Grumman Ship Systems a shipbuilder and the state’s largest employer; Signal International an oil platform builder Mississippi Phosphates a larger producer of diammonium phosphate and one of the largest Chevron refineries in the country. As with most rivers in the south the Pascagoula River requires regular maintenance dredging.

In 2005 Hurricane Katrina’s 20-foot storm surge devastated the city of Pascagoula flooding 92 percent of the city and destroying most of the homes along Beach Boulevard. The storm surge also caused significant damage to Beach Boulevard and threatened the integrity of the seawall.

Foundation material landward of the seawall began to migrate seaward through cracks in the seawall. Additional seaward foundation material at the toe of the seawall was eroded by wave action. The project as designed by the Corps provided a beach to buffer peak wave action thereby maintaining seawall functionality and integrity.

The Corps of Engineers saw the opportunity to use maintenance material from the river to create a beach along the sea wall to protect it from future storm surges. However the dredging area was more than seven miles away from where the beach would be created.

The Corps hired Mike Hooks Inc. of Westlake Louisiana as the prime contractor for the project. Mike Hooks sub-contracted ENCO Dredging of Gulf Shores Alabama after reviewing the plan to pump the material downriver and create a beach that would tie into an existing beach.
ENCO has much experience in beach restoration especially along the Gulf Coast. The company proposed dredging the material from upriver pumping the material 40000 feet (7.6 miles) down river where the silt would be separated from the sand and depositing the sand near the sea wall creating a strip of beach that would eventually tie into an existing beach.

With such a long distance between the dredging and deposit sites ENCO used a fleet that included three dredges and four booster pumps all manufactured by M&S Equipment a DSC Dredge LLC Company. An 18-inch x 16-inch cutterhead dredge removed the material and the other two dredges served as booster pumps along with three additional floating boosters and a land-based booster pump. The boosters were placed about every mile or so to transport the sand a total of 7.5 miles.

According to Rex Watson and Mike Smith of ENCO they pumped 300000 cubic yards of sand. ENCO also pumped material for geotextile tubes which are strung together like sausage links along a length of 7700 feet. The tubes were placed approximately 100 feet seaward of the seawall in the beach template to help control erosion of the newly-developed beach.

The beach was never intended for recreation but instead serves as protection to the sea wall and Beach Boulevard.